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References: <20210824164801.28896-1-lakshmi.sowjanya.d@intel.com>
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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Thu, 16 Sep 2021 23:21:34 +0200
Message-ID: <CACRpkdZEp0FZOefBPP_sR4g6rKzeKQhpdL-XHYO+CRt5MfTrYg@mail.gmail.com>
Subject: Re: [RFC PATCH v1 00/20] Review Request: Add support for Intel PMC
To:     "D, Lakshmi Sowjanya" <lakshmi.sowjanya.d@intel.com>,
        Dipen Patel <dipenp@nvidia.com>
Cc:     "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Mark Gross <mgross@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        "Saha, Tamal" <tamal.saha@intel.com>, bala.senthil@intel.com
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Hi Sowjanya,

thanks for your patches!

On Tue, Aug 24, 2021 at 6:48 PM <lakshmi.sowjanya.d@intel.com> wrote:

> From: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
>
> Starting with Intel(R) Tiger Lake and Elkhart Lake platforms the PMC
> hardware adds the Timed I/O hardware interface.
>
> The Timed I/O hardware implements some functionality similar to GPIO
> with added timing logic that is driven by the Always Running Timer
> (ART).
>
> The Timed I/O Hardware implement 3 basic functions:
>   * Input Timestamping
>   * Single Shot Timed Output
>   * Periodic Timed Output
>
>  Please help to review the changes.

This looks very similar to the usecase proposed for the HTE
Hardware Timestamping Engine, proposed by Dipen Patel
for the nVidia 194 and which is currently in RFC:
https://lore.kernel.org/linux-gpio/20210625235532.19575-1-dipenp@nvidia.com/

Please review this new subsystem and see if you can just
make a slot-in driver using Dipen's patches instead.

Dipen: please have a look at Sowjanya's patches to see
if this hardware is similar to yours.

Sometimes several vendors come up with similar hardware
around the same time, because of industry trends, so I would
not be surprised if these two hardwares address the very
same usecase.

Yours,
Linus Walleij